22-May-2011 - The HIV epidemic is the largest in the world and represents one of the most serious public health problems, according to data from the World Health Organization (WHO). Only 30% of the more than 10 million patients in need have the access to the antiretroviral treatment. The total number of infected people exceeds 30 million and there are about 3 million new infections per year. The best hope for reducing the incidence of AIDS (Acquired Immune Deficiency Syndrome) is a preventive vaccine.
The most effective preventive vaccines act by inducing a response based on neutralizing antibodies. Some groups had shown that HIV-infected patients can produce a broad neutralizing response. But so far, all studies have excluded patients on antiretroviral therapy with undetectable viral load, i.e., having an improved profile compared to untreated patients.
To better understand the induction of neutralizing antibodies in these patients, researchers from IDIBAPS/Hospital Clinic of Barcelona, bound to the program HIVACAT (Research Project AIDS Vaccine), for the first time, have included samples of patients treated with a low level of viral replication. 508 samples were analyzed in 364 patients (191 treated and 173 with no antiretroviral treatment) through a new strategy based on the use of recombinant viruses.
The study represents the first big test and evaluation of the neutralization in HIV-infected persons with undetectable viral load. "We have shown that patients receiving antiretroviral treatment are able to induce a broad and strong humoral immune response (broad-spectrum neutralizing antibodies) for HIV despite having undetectable viremia", says the last author of the study, Eloisa Yuste. In these patients, the low level of antigenic stimulation may be compensated by an improved B cell function induced by antiretroviral treatment.
The report concludes that the percentage of treated and untreated patients that generated broad-spectrum neutralizing antibodies was very similar: 2.3%. This is the first step in identifying the epitope able to induce the development of these antibodies and therefore would be an excellent candidate for potential AIDS preventive vaccine based on the development of broad-spectrum neutralizing antibodies. This is how other highly effective preventive vaccines such as them against human papillomavirus, hepatitis A and B and polio, among others.
Neutralizing antibodies do not work when HIV infection is already established. But their presence induced by a vaccine could prevent infection if an uninfected person comes in contact with the virus. So, the next step is to get the induction of broad-spectrum neutralizing antibodies are generated in patients who have not acquired the virus. "The next stages of the research will characterize these broad-spectrum neutralizing antibodies and identify the virus that has led and could serve as a potential preventive vaccine in healthy people", she concludes.
The Institut d'Biomedical Research August Pi i Sunyer (IDIBAPS) is a public entity of the Generalitat de Catalunya. Its main objective is to integrate quality clinical research with high-level basic research. So get a more effective transfer of scientific breakthroughs in the prevention and treatment of health problems more prevalent.
The IDIBAPS scientists are from the various entities that form Hospital Clinic of Barcelona, Faculty of Medicine, University of Barcelona, Institute for Biomedical Research of Barcelona from CSIC and the staff hired by the Fundació Clínic. IDIBAPS scientific production places it as the most productive biomedical center of Spain and as a reference for his leadership on major national and European projects.
Biomedicine behind these professionals is to minimize the barriers between the laboratory and medical appointments. IDIBAPS aims to facilitate the challenges of medicine is moving smoothly in basic research, and the results obtained in the laboratory is effectively reversed into benefits for patients. Improving the health of people is the ultimate goal.
The proposed research and vaccine development for AIDS, HIVACAT, is composed of two established research centers very important that there are currently over AIDS: the AIDS Research Institute IrsiCaixa Hospital Germans Trias i Pujol and Disease Service Infectious and AIDS of Hospital Clínic de Barcelona. HIVACAT research in developing new HIV vaccine in conjunction with ESTEVE and with the support of the Fundación La Caixa, the Department of Health and the Department of Economics and Knowledge of the Generalitat de Catalunya and the Fundació Clínic. The consortium represents the first significant experience of cooperation in this field between public authorities, researchers and business.
Both research centers develop along at 7.500 patients who benefit from the rapid introduction of new treatments developed at the same sites and gained international innovations. HIVACAT has a team of over 60 scientists trained in internationally renowned research centers such as Harvard University in the United States, the Pasteur Institute in Paris and the Royal Free Hospital in London.
In Spain, the project is co-chaired by Dr. Bonaventura Clotet, Hospital Germans Trias i Pujol and Dr. Josep Maria Gatell the Hospital Clinic. The scientific coordination is provided by the researcher IrsiCaixa ICREA research professor of Christian Brander.
IDIBAPS - Institut d'Investigacions Biomèdiques August Pi i Sunyer